Earth drill drive



March 1967 F. H. FEHRMANN ET AL 33%,89

EARTH DRILL DRIVE Filed June 14, 1965 51mm CHARLES L. PASS/EUR FRED FEHPMANN' W United States Patent Ofiice 3,309,898 Patented Mar. 21, 1967 3,309,898 EARTH DRILL DRIVE Fred H. Fehrmann, St. Ann, and Charles L. Rassieur,

University City, Mo., assignors to Central Mine Equipment Company, St. Louis, Mo., a corporation of lVIissouri Filed June 14, 1965, Ser. No. 463,525 7 Claims. (Cl. 64--11) This invention relates to a drive for a vertical, portable, rotary earth drill, which drive includes a flexible coupling releasably to couple a driving member and a driven member between which some disalignment is expected and is allowable.

In portable earth drilling rigs it is common to connect a vertical drive stud from a gear box mounted on a drill frame, carried by a vehicle, to a vertical Kelly bar, from which a rotary table is driven. It is common to use a flexible coupling to connect the drive stud to the Kelly bar. The flexible coupling is necessary to adjust for misalignment between the drive stud and the Kelly bar. The portable earth drilling rigs are commonly mounted on a vehicle. It is an advantage to be able to fold the upright portion of the drill, which includes the Kelly bar, into a more of less horizontal position to reduce the over-all height of the drill and vehicle when the vehicle is driven from place to place. If the upright portion of the drill is to be folded, the mechanical drive train must be disconnected. It is advantageous to disconnectthe drive train between the Kelly bar and the gear box, to keep as small as possible the proportion between the part of the drill that does not fold and the part of the drill that does fold.

A rotary box travels up and down on the Kelly bar. A disconnectable coupling device placed above the flexible coupling Will shorten the vertical movement of the box. To lengthen this movement to compensate for a device placed above the coupling requires lengthening of the Kelly bar, structural frame, hydraulic cylinders, and the like, thus increasing the cost of the drill and making it a less compact unit. Such a lengthening also raises the height of the rotary table in the down position making access to the top of the spindle diflicult.

One of the objects of this invention is to provide a portable earth drill drive which permits quick and easy connection and disconnection of a mechanical drive train and a Kelly bar.

Another object is to provide such a drive which requires n lengthening of the upright part of the drill, beyond the present height.

Still another object is to provide such a drive in which means for connecting and disconnecting the drive train and the Kelly bar requires no parts in addition to a flexible coupling which is required in any even to accommodate misalignment.

Other objects will become apparent to those skilled in the art in the light of the following description and accompanying drawing.

In accordance with this invention, generally stated, a rotary, portable, earth drill drive is provided with driving and driven members of non-circular, preferably polygonal and in particular, square, configuration, and a flexible coupling with upper and lower sections each with a hole through it adapted selectively slideably and engagingly to receive one of said members. The hole adapted to receive the lower, driving member is larger than the hole adapted to receive the upper, driven member and is of such a shape and size as to permit the flexible coupling itself to he slid up the driven member beyond the bottom end of the driven member to uncouple the driving and driven members.

In the drawings:

FIGURE 1 is a view in side elevation of one illustrative embodiment of drive of this invention in operating position;

FIGURE 2 is a view in perspective of the drive shown in FIGURE 1, in separated position; and

FIGURE 3 is a sectional view taken along the line 33 of FIGURE 1.

Referring now to the drawing for one illustrative embodiment of earth drill drive of this invention, reference numeral 1 indicates a large lower square shaft, which constitutes the driving member. The lower shaft 1 is rotatably mounted in and driven by conventional drive mechanism of a gear housing fixedly mounted on a base drill frame which in turn is mounted on a vehicle. The lower shaft 1 has a circumferential shoulder 12 spaced below the upper end of the shaft. An upper, square shaft 2 constitutes the driven member. The upper shaft 2 is smaller in cross-section than the lower shaft 1, but is long and substantially uniform in cross-section throughout its length, serving as the Kelly bar by which the drill is driven. The upper shaft (Kelly bar) 2 is journalled in a bearing within a bearing frame, all of which is conventional. The bearing frame and Kelly bar are desirably folded down over the vehicle when the drilling rig is not in use, so as to reduce the effective height of the vehicle when it is being taken from place to place. The part of the upper shaft 2 shown in FIGURE 1 projects below the bearing and terminates short of the upper end of the lower shaft 1 when the two shafts are in operative position. The bearing frame is pivoted to some fixed structure on the base drill frame so that when the bearing frame is rotated about that pivot, the upper shaft 2 moves in an arcuate path upwardly away from the lower shaft 1. In order to couple the two shafts when they are to be operated and permit their disconnection when the upper shaft is to be moved from the lower shaft, 3. flexible coupling 10 is provided. The coupling 10 includes an upper coupling section 3, with a hub 13 and a sprocket section upon which are teeth 6, a lower coupling section 4 with a hub 14 and a sprocket section upon which there are teeth 6, and a chain 5, surrounding the sprocket sections of the coupling sections 3 and 4, and engaging the teeth 6.

As shown particularly in FIGURE 3, a shaft hole 9 is provided in the coupling section 3 to receive shaft 2, and a lower shaft hole '8 is provided in coupling section 4 to receive lower shaft 1. The holes 9 and 8 are proportioned to receive the respective shafts with suflicient clearance to provide an easy sliding fit. The holes are centered with respect to one another, their corresponding defining walls are parallel and the holes extend entirely through the coupling section. The hole 8 is larger than the hole 9, but not sufiiciently large to accommodate the part of the lower shaft 1 below the shoulder 12, so that the hub 14 rests upon the shoulder 12, supporting the coupling.

A disengagement latching pin 7 is shown in FIGURE 2 as inserted in a transverse latch pin passage 11 in the upper shaft 2.

In the operation of the drill drive illustrated and described, the shaft 2 is initially in a position away from the shaft 1. The coupling 10 is slid onto the end of the shaft 2 with the hub 13 of the upper section 3 uppermost. The shaft 2 extends first into the hole 9 and then as the entire coupling is slid up away from the end of shaft 2, the shaft 2 projects also through the hole 8, and the shaft 2 may then be swung into position directly above shaft 1. The coupling is then allowed to slide downwardly until the hub 14 of coupling section 4 strikes the shoulder 12. If the shafts were not coordinated with respect to the holes 8 and 9, so that the hub 14 hits the top of the shaft 1, either shaft 1 or the coupling with shaft 2 is rotated 3 until they are coordinated, when the coupling section 4 slides down onto the shaft 1, until the hub 14 strikes the shoulder 12.

In order to disengage the coupling, the entire coupling is slid away from shaft 1, upwardly on shaft 2, until there is sufficient clearance for pin 7 to be inserted in pin passage 11 in shaft 2. Pin 7 retains the coupling out of engagement with shaft 1 until the pin is withdrawn and the coupling either removed or used to recouple the shafts.

As is readily apparent, no mounting means are necessary to hold the coupling in place on shafts 1 and 2, during operation of the drill. The force of gravity retains the coupling in engagement. Chain 5, engaging teeth 6, provides the requisite flexibility of the coupling. An example of this general type of coupling, known as a double chain and sprocket coupling, heretofore used in other applications, is illustrated in US. Patent No. 3,167,935.

It has been found that by making the lower shaft 1 larger than the upper shaft 2 in cross-section, and the hole 8 correspondingly larger than the hole 9, several advantages are gained. The coupling has been found to mate with the lower shaft with unexpected ease as compared with couplings in which the two shafts and holes are of the same size.

Purely by way of illustration and not by way of limitation the dimensions of the coupling may be as follows:

Upper shaft 2 1%" square. Lower shaft 1 1%" square. Upper coupling section 3 3 /2" O.D.

Lower coupling section 4 3 /2 O.D.

Hole 8 1%"+.01" square. Hole 9 1 /s"+.0l square. Thickness of coupling section 3 2".

Thickness of coupling section 4 2".

Pin 7 A" diameter.

Numerous variations in the construction of the earth drill drive of this invention, within the scope of the appended claims, will occur to those skilled in the art, in the light of the foregoing disclosure. For example, shafts provided with flat spots or polygonal shafts with more or fewer than four sides, eliptical shafts or a splined lower shaft could be used in place of square shafts. However, the square shaft has advantages in ease of positioning, large areas of engagement, strength, and ease of construction, the combination of which is not found in other shapes. A pin, like pin 7, could also be placed in a hole provided above the coupling when the coupling is in place, to insure that the coupling is not inadvertently displaced. These variations are merely illustrative,

Having thus described the invention, what is claimed and desired to be secured by Letters .Patent is:

1. A flexible drive assembly for use with an earth drilling device, comprising a lower drive shaft, an upper driven shaft, said upper shaft adapted to be swung away from said lower shaft, and a flexible coupling interconnecting said shafts, said flexible coupling comprising an upper section having a hub portion, said hub portion having a non-circular hole through it conforming in shape and size to a cross section of a lower end of said upper shaft and adapted to slidably receive said lower end, and a lower section having a hub portion, said hub portion having a non-circular hole through it conforming in shape and size to a cross section of an upper end of said lower shaft and adapted to slidably receive said upper end, said upper conforming hole being smaller in each corresponding cross sectional dimension than said lower conforming hole, and abutment means on said lower shaft, said abutment means adapted to engage the hub portion of said lower section to limit the axial movement of said coupling in one direction.

2. The drive assembly of claim .1 wherein the flexible coupling is of the double chain and sprocket type.

3. The drive assembly of claim 1 wherein said abutment means comprises an outwardly extending shoulder downwardly spaced from the upper end of the lower shaft.

4. The drive assembly of claim 1 wherein said ends of said shafts are polygonal in cross section.

5. The drive assembly of claim 3' wherein said upper shaft is of uniform cross section from its lower end to a height at least equal to the sum of the length of said upper hub portion and the distance from the upper end of said lower shaft to said shoulder on said lower shaft.

6. The drive assembly of claim 3 wherein said ends of said shafts are square in cross section.

7. The drive assembly of claim 6 wherein the upper driven shaft is of uniform cross-section throughout its length and is provided with a transverse hole adapted removably to receive a pin, said hole being located below a position to which the coupling can be slid.

References Cited by the Examiner UNITED STATES PATENTS 1,178,283 4/1916 Winter 64--6 2,227,333 12/1940 Campbell 6419 2,335,171 11/1943 Cornett 173-28 2,394,448 2/ 1946 Herold et a1. 6423 3,167,935 2/1965 Fawick 64--19 FRED C. MATTERN, JR., Primary Examiner, HALL COE, Examiner, 

1. A FLEXIBLE DRIVE ASSEMBLY FOR USE WITH AN EARTH DRILLING DEVICE, COMPRISING A LOWER DRIVE SHAFT, AN UPPER DRIVEN SHAFT, SAID UPPER SHAFT ADAPTED TO BE SWUNG AWAY FROM SAID LOWER SHAFT, AND A FLEXIBLE COUPLING INTERCONNECTING SAID SHAFTS, SAID FLEXIBLE COUPLING COMPRISING AN UPPER SECTION HAVING A HUB PORTION, SAID HUB PORTION HAVING A NON-CIRCULAR HOLE THROUGH IT CONFORMING IN SHAPE AND SIZE TO A CROSS SECTION OF A LOWER END OF SAID UPPER SHAFT AND ADAPTED TO SLIDABLY RECEIVE SAID LOWER END, AND A LOWER SECTION HAVING A HUB PORTION, SAID HUB PORTION HAVING A NON-CIRCULAR HOLE THROUGH IT CONFORMING IN SHAPE AND SIZE TO A CROSS SECTION OF AN UPPER END OF SAID LOWER SHAFT AND ADAPTED TO SLIDABLY RECEIVE SAID UPPER END, SAID UPPER CONFORMING HOLE BEING SMALLER IN EACH CORRESPONDING CROSS SECTIONAL DIMENSION THAN SAID LOWER CONFORMING HOLE, AND ABUTMENT MEANS ON SAID LOWER SHAFT, SAID ABUTMENT MEANS ADAPTED TO ENGAGE THE HUB PORTION OF SAID LOWER SECTION TO LIMIT THE AXIAL MOVEMENT OF SAID COUPLING IN ONE DIRECTION. 